Add ifrname_override option to work around some sockets ioctl errors

Author: elicn

qiling/os/posix/posix.py

@@ -99,12 +99,15 @@ def __init__(self, ql: Qiling):
         self.ql = ql
         self.sigaction_act = [0] * 256
 
-        self.uid = self.euid = self.profile.getint("KERNEL","uid")
-        self.gid = self.egid = self.profile.getint("KERNEL","gid")
-
-        self.pid = self.profile.getint("KERNEL", "pid")
-        self.ipv6 = self.profile.getboolean("NETWORK", "ipv6")
-        self.bindtolocalhost = self.profile.getboolean("NETWORK", "bindtolocalhost")
+        conf = self.profile['KERNEL']
+        self.uid = self.euid = conf.getint('uid')
+        self.gid = self.egid = conf.getint('gid')
+        self.pid = conf.getint('pid')
+
+        conf = self.profile['NETWORK']
+        self.ipv6 = conf.getboolean('ipv6')
+        self.bindtolocalhost = conf.getboolean('bindtolocalhost')
+        self.ifrname_ovr = conf.get('ifrname_override')
 
         self.posix_syscall_hooks = {
             QL_INTERCEPT.CALL : {},

qiling/os/posix/syscall/ioctl.py

@@ -81,6 +81,15 @@ def ioctl(_fd: int, _cmd: int, _arg: int):
     if isinstance(ql.os.fd[fd], ql_socket) and cmd in (SIOCGIFADDR, SIOCGIFNETMASK):
         data = ql.mem.read(arg, 64)
 
+        ifr_name_override = ql.os.ifrname_ovr
+
+        if ifr_name_override is not None:
+            # make sure the interface name does not exceed 16 characters.
+            # pad it with null bytes if shorter
+            ifr_name_override = ifr_name_override[:16].ljust(16, '\x00')
+
+            data[0:16] = ifr_name_override.encode()
+
         try:
             data = ql.os.fd[fd].ioctl(cmd, bytes(data))
         except OSError as ex:

qiling/profiles/linux.ql

@@ -32,6 +32,11 @@ current_path = /
 
 
 [NETWORK]
+# override the ifr_name field in ifreq structures to match the hosts network interface name.
+# that fixes certain socket ioctl errors where the requested interface name does not match the
+# one on the host. comment out to avoid override
+ifrname_override = eth0
+
 # To use IPv6 or not, to avoid binary double bind. ipv6 and ipv4 bind the same port at the same time
 bindtolocalhost = True
 # Bind to localhost